1. Field of the Invention
The present invention generally relates to a vehicle heat pump system. More specifically, the present invention relates to a vehicle heat pump system that captures heat from air exhausting from the passenger compartment of the vehicle when operating in a heating mode.
2. Background Information
A vehicle typically includes both an air conditioning system and heating system in order to provide comfortable conditions within a passenger compartment of the vehicle. However in electric vehicles, there is no internal combustion engine and hence no source of disposable heat that can be used to heat the passenger compartment. Similarly, in some hybrid vehicles, an internal combustion engine may be so small that it may fail to provide adequate amounts of disposable heat to heat the passenger compartment or may not operate long enough to achieve a temperature where disposable heat is produced for heating the passenger compartment.
Heat pump systems have been proposed for electric vehicles and hybrid vehicles. However these systems are overly complex and include exposing segments of a heating circuit to ambient conditions outside the passenger compartment resulting in loss of heat that could otherwise be used to heat the passenger compartment.